After replacing water pump, HD fan clutch, 180 thermostat, new coolant, I still have a very high idle at about 1500 rpms that randomly spikes, and engine temps that will go above 220 with the ac on.

I suspect the high idle doesnt help my temps but does anyone have any other advice to keep my temps down?

4.0 v8 1997 discovery 1 CDL 175k

 

What is the condition of the radiator and hoses?
Air in the system?
Fluid reservoir housing?
Is fluid cap properly sealed?

Is are you seeing 1500rpms? At startup / standing in traffic / with ac on / etc.

 

First thing is to assure you have bled the system thoroughly. They can be a devil.

It can help to park the truck with the front elevated to the extent it is possible.

Start engine, turn heat in the cabin all the way up and fan on high.

Increase engine speed to 2500 rpm and hold there until hot air comes out of the vents. When it does, turn off engine and top off coolant level in the reservoir.

 

I may have to try this method next time as it seems so much faster.

The way I was doing it was turning the heat all the way up and only having the blower turned to position #1. No paddle action.

Thanks

 

After bleeding twice in two days with the front end elevated as much as I could the results are very good. I took it about 30 miles out into the desert, on the highway it never went past 195 and even parked it didn’t pass 195. After riding trails for about 2 hours the highest temp I saw was 206. That’s crawling, low speeds, parked, and never shut it off. Happy to say she’s finally past all her temp problems. Broke a TF shock but I suspect the previous owner either tightened them down way to much or never off-roaded. New shock kit on the way from OME thanks for the help

 

Are your RPMs more settled now?

 

So when I’m park and neutral my rpms are still pretty high, around 1500 sometimes a little lower. Which worries me long term about how much work the engine is doing. But I don’t think it’s a vacuum leak because it would have a high idle in any gear. Maybe the throttle position sensor but I’d rather not waste 100 bucks just throwing a part at it yet

 

wilson, no need to spend $100, yet. You have a '97 so you have OBDII.

Check out this thread (lots of great info) and particularly post #11. $25 dongle and $5 app will help you solve a lot of the mysteries. You will be able to see what reading your TPS is sending the ECU.

https://landroverforums.com/forum/di...section-32402/

 

I just went through the pain (for me at least) of trying to get this to run and am happy to help out if needed since it is fresh in my memory.

 

What was your High RPMs solution?